INCINERATION OF INFECTIOUS WASTE.

In 1985, there were 6872 hospitals in the U.S. with 1.3 million
beds. If beds are occupied 70% of the time and each occupied bed
creates 13 pounds of waste per day, U.S. hospitals produce 2.2
million tons of waste per year. An estimated 15% of this is
infectious waste containing human anatomical waste, plus
garments, gauze pads, diapers, catheters, and so forth. But the
infectious 15% cannot be segregated from the non-infectious, so
it all gets mixed together, creating a larger mass that must all
be considered infectious.

An estimated 90% of all hospitals run their own incinerators;
this means about 6,200 neighborhoods are impacted by such
machines. From the viewpoint of people living near hospitals,
there are five items of concern: (1) the emission of bacteria or
viruses that might make people sick; (2) the emission of low
molecular weight organic molecules (trichloroethylene [a
suspected carcinogen], and tetrachloroethylene, among others);
(3) the emission of high molecular weight organic molecules, (so
called "products of incomplete combustion," benzopyrenes, PCBs,
polynuclear aromatic hydrocarbons and other polycyclic organic
matter, much of which is carcinogenic); (4) the emission of toxic
particles small enough for a person to breathe deep into their
lungs; (5) and the emission of dioxins and furans.

The U.S. Environmental Protection Agency (EPA) recently released
a report completed under contract by the Radian Corporation. The
aim was to gather what is known about pollution from hospital
incinerators. The authors searched the scientific literature,
and interviewed many knowledgeable experts: staff of regulatory
agencies (EPA, state and local), the American Hospital
Association, and incinerator vendors.

Of the estimated 6200 hospital incinerators in use, perhaps 1200
are large incinerators (burning more than 400 pounds per hour or
400 tons per year) and 5000 are smaller. Hospital incinerators
fall into three types: rotary kiln, excess air and starved air.
By far the commonest (especially among units installed during the
last 15 years) is starved air (also called "controlled air,"
"two-stage" and "modular"). Excess air incinerators (also called
"pyrolitic incinerators," and "multi-chamber incinerators") come
in two types: large units, which are generally "in-line," and
smaller units, which are generally "retort" types.

Radian could find no air emissions data for small excess-air
incinerators, the kind that serve perhaps 75% or more of the
nation's hospitals. Therefore, the remainder of this article
describes air emissions from large controlled-air incinerators.

Even among these few incinerators, the lack of data is shocking.
Let's look at the five categories mentioned above.

BACTERIA AND VIRUSES. You might think emission of
disease-causing organisms (pathogens) from hospital incinerators
would be the subject of intense scrutiny. Not so. The Radian
corporation could find only two studies in the scientific
literature. One study found twice as many bacteria leaving an
incinerator smoke stack as were found in normal outdoor air
(though the results were not statistically significant; in other
words, they may have occurred by chance). The second study
showed that, in a two-chamber incinerator, the temperature in the
first chamber has to be 1400 degrees Fahrenheit and in the second
chamber had to be 1600 deg. F. to guarantee sterilization of
bacteria and viruses. (Many incinerators are not designed to
exceed 1400 deg. in their secondary chamber, so presumably do not
effectively sterilize wastes they burn.) That ends the discussion
of bacteria and viruses in the Radian study. The entire section
on pathogens takes up 14 lines of text in a 151-page report.

PRODUCTS OF INCOMPLETE COMBUSTION, BENZOPYRENE, PCBS AND OTHER
CARCINOGENIC ORGANIC MOLECULES: These pollutants are "important,"
says Radian, but are not included in the study "due to lack of
emissions data."

TINY TOXIC particles: A micron is a millionth of a meter (and a
meter is about a yard). If you breathe particles (soot) in the
size range of 2 to 10 microns in diameter, they are filtered out
by the respiratory system (nose, esophagus, etc.) and are moved
into the mouth, then swallowed. Particles smaller than 2 microns
are considered "respirable" because they can enter the deep
lungs. The smallest particles (1 micron or less) enter the
deepest part of the lung, the alveoli, the 3 million little sacs
that pass oxygen into the blood and let carbon dioxide pass back
out. Particles that enter the alveoli may eventually be removed
by natural cleansing mechanisms, or they may lodge there,
contributing a grey color to the normallypink lungs, or they may
actually pass into the blood stream and go someplace else in the
body.

As luck would have it, the respirable particles from an
incinerator contain more than their fair share of toxic
materials, especially toxic metals and the oftencarcinogenic
polycyclic organic molecules. The small particles have a larger
surface area in relation to their bulk than do larger particles.
(A physicist would say small particles have a larger surface-to
volume ratio.) The relatively large surface area of the smallest
particles attracts toxic heavy metals during combustion. Thus,
respirable particles end up LOADED (Radian says "enriched") with
lead, arsenic, cadmium, chromium and other dangerous metals.
(Radian presents no data on enrichment by polycyclic organics,
unfortunately.) Thus the particles that reach deepest into the
lungs are the most toxic. Typical hospital incinerators emit 1.5
to 36 pounds of particles per ton of waste incinerated.
(Incidentally, bacteria and viruses have diameters ranging from
0.4 microns down to 0.02 microns, so they are definitely
respirable.)

DIOXINS AND FURANS: The Radian study describes in detail the
combustion conditions under which dioxins and furans will be
formed. They conclude that the primary chamber of a hospital
incinerator is PERFECT for manufacturing dioxins and furans, and
that safety depends upon the secondary chamber completely
destroying the dioxins by maintaining ideal combustion
conditions. They conclude that the average amount of total
dioxins emitted from a 1000 poundper-hour hospital incinerator
operating 2000 hours per year would be 3.7 grams of dioxin per
year. (There are 28 grams in an ounce.) This may not sound like
much, but dioxin is considered extremely toxic, so it may be a
lot, depending on where it goes once it is released into your
neighborhood.

Conclusion: The nation's primary medical care institutions are
almost all operating incinerators without knowing what they are
doing, literally. The data are simply not available. What data
there are, on respirable particles and dioxins, indicate the need
for very tight air pollution control, which is not provided under
federal law, nor under most state laws. In short, hospital
incineration of infectious wastes is a scandal.